1. Field Of The Invention
This invention relates to a fluid storage and dispensing system that may be utilized to store high pressure liquid or gas, for dispensing of fluid from the system and use of the dispensed gas in an application such as the manufacture of semiconductor devices and materials.
2. Description of the Related Art
In a wide variety of industrial processes and applications, there is a need for a reliable source of process fluid(s).
For example, a safe, reliable and efficient fluid supply source is desirable in the field of semiconductor manufacturing, ion implantation, manufacture of flat panel displays, medical intervention and therapy, water treatment, emergency breathing equipment, welding operations, space-based delivery of liquids and gases, etc.
U.S. patent application Ser. No. 09/067,393 filed Apr. 28, 1998 in the names of Luping Wang and Glenn M. Tom describes a fluid storage and gas dispensing system including a storage and dispensing vessel for holding a fluid, e.g., a liquid at appropriate pressure whose vapor constitutes the fluid to be dispensed, or alternatively a compressed gas. The vessel includes an outlet port and is equipped with a dispensing assembly coupled to the outlet port, for example a valve head assembly including a dispensing valve and an outlet for selective discharge of gas deriving from liquid or compressed gas in the vessel.
In the Wang et al. system, a fluid pressure regulator is associated with the outlet port, and may be at least partially interiorly disposed in the vessel, optionally coupled with a phase separator assembly to prevent liquid from leaking to the dispensing valve and outlet when the fluid in the vessel is in the form of a liquefied gas. The fluid regulator preferably is fully interiorly disposed in the vessel, to minimize the possibility of impact and environmental exposure in use, and to minimize the leak path of the contained fluid from the vessel, so that a single weld or seam can be used at the outlet port, to seal the vessel.
The regulator is a flow control device, which can be set at a predetermined pressure level, to dispense gas or vapor from the cylinder at such pressure level. The pressure level set point may be superatmospheric, subatmospheric or atmospheric pressure, depending on the dispensing conditions, and the mode of gas discharge from the vessel.
U.S. patent application Ser. No. 09/300,994 filed Apr. 28, 1999 in the names of Luping Wang and Glenn M. Tom for xe2x80x9cFLUID STORAGE AND DISPENSING SYSTEM,xe2x80x9d is a continuation in part of the above-described U.S. patent application Ser. No. 09/067,393, and describes further aspects of the xe2x80x9cregulator in a bottlexe2x80x9d apparatus, including arrangements employing a double-stage (or multi-stage) fluid pressure regulator, optionally with a particulate filter assembly, interiorly disposed in the vessel. Such continuation in part application also discloses fluid storage and dispensing vessel arrangements in which the vessel encloses an interior volume of less than about 50 liters and has an inlet opening larger than 1.5 inch NGT, as well as embodiments in which the fluid storage and dispensing vessel contains a physical adsorbent material holding adsorbed gas at an internal pressure of from about 50 psig to about 5000 psig.
In the practice of the regulator in a bottle system of the above-discussed U.S. patent application Ser. No. 09/300,994 and U.S. patent application Ser. No. 09/067,393, there is a need for further improvement in certain aspects of the structure and operation of the fluid storage and dispensing system.
More specifically, such fluid storage and dispensing systems with internally disposed regulator elements find use in a variety of gas supply applications, in which one or more xe2x80x9cembeddedxe2x80x9d set pressure regulators (SPRs) each comprising a pressure sensing assembly (PSA) in the regulator body may be disposed in the interior volume of the storage and dispensing vessel, and utilized to regulate the pressure and flow rate of gas deriving from the contained fluid, in the fluid dispensing operation.
The ability to set the PSA of the embedded SPR to sub-atmospheric pressures, e.g., 600 Torr, is most desirable during installation and change-out of the vessel (involving coupling of the vessel to a gas dispensing flow circuit, or uncoupling of the vessel therefrom when the vessel has become depleted of fluid) or in other instances where a reliable vessel connection has not been made. For certain toxic hydride gases, it is also desirable to maintain a sub-atmospheric pressure setting during gas delivery to minimize the potential for catastrophic release during use. However, for many hydride gases, the main hazards of which are pyrophoricity or flammability, and for corrosive gases, a sub-atmospheric set point for the SPR will not allow for constant, high flow of dispensed gas to multiple points. In these instances, it is preferable to deliver these fluids at slightly positive pressures, once reliable vessel connections have been made. There are thus differing pressure levels that are appropriate or desirable for storage of fluid in the vessel as opposed to dispensing of fluid from the vessel.
The existing xe2x80x9cregulator in a bottlexe2x80x9d systems do not accommodate such desired differing set points for the regulator, since it is pre-set at a single set point prior to its installation in the vessel.
An additional issue accompanying the use of interiorly disposed regulator devices is the incidence of liquefaction and droplet condensation during the dispensing operation, as pressure on the compressed gas or liquefied compressed gas is reduced during flow thereof through the SPR.
Such liquefaction of liquefied compressed gases and liquid droplet formation from compressed gases attributable to pressure reduction is attributable to change in enthalpy of the fluid, in accordance with the well-known Joule-Thompson effect.
The incidence of the Joule-Thompson effect can limit flow conductance and capacity of the SPR, and degrade its performance and lifetime.
There is therefore a need in the art to provide improved fluid storage and delivery systems for selective dispensing of fluids that overcome the various deficiencies described above.
It is accordingly an object of the present invention to provide an improved fluid storage and dispensing system for selective dispensing of fluids, which overcomes such problems.
It is another object of the invention to provide a fluid storage and dispensing system that allows for sub-atmospheric SPR set-point pressure during storage and transportation and super-atmospheric SPR set-point pressure during use.
It is another object of the invention to provide an improved fluid storage and dispensing system for the selective dispensing of fluids, characterized by significant advantages in cost, ease of use, and performance.
Other objects and advantages of the invention will be more fully apparent from the ensuing disclosure and appended claims.
The present invention relates to a system for storage and dispensing of a fluid, for use in applications such as the manufacture of semiconductor products.
In one aspect, the present invention relates to a fluid storage and dispensing system, comprising:
a fluid storage and dispensing vessel enclosing an interior volume for holding a fluid, wherein the vessel includes a fluid discharge port for discharging fluid from the vessel;
a pressure regulating element in the interior volume of the fluid storage and dispensing vessel, arranged to flow fluid therethrough to the fluid discharge port at a set pressure for dispensing thereof; and
a controller external of the fluid storage and dispensing vessel, arranged to transmit a control input into the vessel to cause the pressure regulating element to change the set pressure of the fluid flowed from the pressure regulating element to the fluid discharge port.
In another aspect, the invention relates to a fluid storage and dispensing system, comprising an enclosed vessel for holding a fluid, and a pressure monitoring assembly in the vessel including (i) a pressure sensor arranged for contact with fluid in the vessel, (ii) a piezoemitter operatively coupled with the pressure sensor and arranged to emit externally of the vessel a sonic signal correlative of pressure sensed by the pressure sensor, and (iii) a power supply operatively coupled with the pressure sensor.
A further aspect of the invention relates to a fluid storage and dispensing system, comprising:
a fluid storage and dispensing vessel enclosing an interior volume for holding a fluid, wherein the vessel includes a fluid discharge port for discharging fluid from the vessel;
an adjustable set point pressure regulator in the interior volume of the fluid storage and dispensing vessel, arranged to flow fluid therethrough to the fluid discharge port at a set point pressure for dispensing thereof; and
a regulator adjustment assembly in the interior volume of the fluid storage and dispensing vessel, remotely controllable from outside of the vessel, and arranged to flow fluid from the interior volume of the vessel to the adjustable set point pressure regulator to change the set point pressure of the regulator.
Yet another aspect of the invention relates to a fluid storage and dispensing system, comprising:
a storage and dispensing vessel for holding a fluid and having a discharge port for dispensing fluid from the vessel;
a thermal controller for controlling temperature of fluid in the vessel;
a diffusion tube in the vessel, joined to the discharge port, and arranged for diffusion of fluid into the tube and flow from the tube to the discharge port for dispensing from the vessel;
a pressure sensor for sensing pressure of fluid dispensed from the vessel and operatively coupled with the thermal controller to selectively vary the temperature of the fluid in the vessel to correlatively vary diffusion of fluid into the diffusion tube and resultingly obtain a predetermined pressure in the fluid dispensed from the vessel.
One aspect of the invention relates to a method of supplying a fluid for use thereof, comprising:
confining a fluid in a fluid storage and dispensing vessel enclosing an interior volume for holding a fluid, wherein the vessel includes a fluid discharge port for discharging fluid from the vessel, and a pressure regulating element in the interior volume of the fluid storage and dispensing vessel, arranged to flow fluid therethrough to the fluid discharge port at a set pressure for dispensing thereof; and
transmitting a control input from an exterior locus into the vessel to cause the pressure regulating element to change the set pressure of the fluid flowed from the pressure regulating element to the fluid discharge port.
A still further aspect of the invention relates to a method of monitoring fluid pressure in an enclosed vessel for holding a fluid, said method comprising sensing pressure of the fluid and transmitting within the vessel a signal correlative thereof to a piezoemitter within the vessel so that the piezoemitter transmits out of the vessel a sonic signal correlative of pressure sensed by the pressure sensor.
An additional aspect of the invention relates to a method of supplying fluid from a storage and dispensing vessel enclosing an interior volume for holding a fluid, and including a fluid discharge port for discharging fluid from the vessel, said method comprising:
disposing an adjustable set point pressure regulator in the interior volume of the fluid storage and dispensing vessel, arranged to flow fluid therethrough to the fluid discharge port at a set point pressure for dispensing thereof;
disposing a remotely actuatable fluid flow control assembly in the interior volume of the fluid storage and dispensing vessel, wherein the fluid flow control assembly is coupled in latent flow communication with the adjustable set point regulator; and
remotely actuating the fluid flow control assembly to flow fluid from the interior volume of the vessel to the adjustable set point pressure regulator to change the set point pressure of the regulator.
Another aspect of the invention relates to a method of supplying fluid from a storage and dispensing vessel enclosing an interior volume for holding a fluid, and including a fluid discharge port for discharging fluid from the vessel, such method comprising:
disposing a diffusion tube in the vessel, joined to the discharge port, and arranged for diffusion of fluid into the tube and flow from the tube to the discharge port for dispensing from the vessel;
sensing pressure of fluid dispensed from the vessel; and
varying the temperature of the fluid in the vessel in response to the sensed pressure, to correlatively vary diffusion of fluid into the diffusion tube to maintain a predetermined pressure in the fluid dispensed from the vessel.
Other aspects, features and embodiments in the invention will be more fully apparent from the ensuing disclosure and appended claims.